Donald Trump, in an interview with Fox News, doubled down on his criticism of U.S. trade policies while making clear he's not backing down from a simmering feud with the Chamber of Commerce over the issue. 

“The trade deals are ripping our jobs apart,” Trump told Fox News on Wednesday. As for the chamber, he said the group is “totally controlled by the special interest groups.” 

Trump and the Chamber of Commerce have been trading shots all week, underscoring a divide in the Republican Party on the trade issue. The chamber, a traditionally friendly group for mainstream GOP candidates, went after Trump hard on Tuesday over proposals the group said would cost jobs and hurt the economy. 

Trump, though, reiterated Wednesday he believes new trade deals should be negotiated because foreign countries are taking advantage of the United States.

“I’ve got it, I understand it, you see the crowds I am getting, nobody has crowds like we have,” Trump told Fox News. “And it’s about, really, I think in this case trade.” 

Trump initially went after the chamber on Tuesday during a rally in Bangor, Maine. The New York real estate developer accused the organization of being a special interest that only “wants to have the deals that they want to have.”

“They want to have TPP, the Trans-Pacific Partnership, one of the worst deals, and it’ll be the worst deal since NAFTA,” Trump said, claiming the chamber’s motives were “pretty sinister.”

The chamber, the world’s largest business organization, represents the interests of more than 3 million businesses and has members ranging from mom-and-pop shops to large corporations. The group rejects the "special interest" charge. 

Trump once again is waging somewhat of a two-front war, taking on traditional GOP allies while also facing the scorn of President Obama. On Wednesday, Obama slammed Trump’s call for a withdrawal from trade deals as “the wrong medicine.”

"Ordinary people who have concerns about trade have a legitimate gripe about globalization," Obama said pointing to "growing inequality and stagnant wages."

"The question is, what do you do about it? And the prescription of withdrawing from trade deals and focusing solely on your local market -- that's the wrong medicine," he said, during a trip to Canada to meet with North Americans heads of state.

Obama added that Trump’s idea is “not feasible” because local businesses would lose jobs if they didn’t have access to international markets.

For its part, the chamber ripped Trump’s Tuesday trade policy speech in real time on Twitter, picking it apart point by point. His comments were also slammed by the National Association of Manufacturers President Jay Timmons, who tweeted that Trump’s got “it backward.”

Trump’s comments also have not been received well by some wealthy Republican donors like billionaire Paul Singer, who told CNBC Wednesday that Trump's plan for trade deals would not end well.

"The most impactful of the economic policies that I recall him coming out for are these anti-trade policies," Singer said during a panel discussion at the Aspen Ideas Festival in Colorado.

But Trump’s tough talk has gotten the attention of some experts like Art Laffer, the former economic adviser to President Reagan.

Laffer told Newsweek while he didn’t like the “tone” of Trump’s Tuesday speech, he saw some improvements.

"I saw negotiating better trade deals rather than throwing away all the trade deals we have now. He points out the flaws in these trades, and that’s all true," Laffer said. "I don’t like the tone of it, but I dislike the tone less today than I did three weeks ago.”

Fox News' Peter Doocy and Christopher Snyder contributed to this report.